Apparatus for and method of freezing carbon dioxide



Sept. '13, 1932.

c. JONES 1,877,180

APPARATUS FOR AND METHOD OF FREEZING CARBON DIOXIDE Filed March 15, 1929 ji 2 f0 INVENTOR lkarlezs'fiwfanes.

Patented Sept. 13, 1932 UNITED STATES OF PITTSBURGH, PENNSYLVANIA, ASS IGNOB TO DBYICE CORPO- NEW YORK, N. Y., A CORPORATION CHARLES L. JONES,

BATION OF AMERICA,

PATENT OFFICE OF DELAWARE APPARATUS FOR AND METHOD OF FREEZING CARBON DIOXIDE Application filed March 13, 1929. Serial No. 846,546.

My present invention relates to the making of solid carbon'dioxide from carbon dioxide liquid, by expansion and gasification of part of the liquid to freeze and solidify the remainder. It was primarily designed for operation by discharging the liquid through a constricted expanding nozzle releasing. the pressure and permittin expansion far below the triple point for car on dioxide, which is approximately 7 pounds per square inch. It will be obvious,

, tures of my invention and in fact the specific the liquid as gas .mainder.

-al type apparatus without change may be used for solidifying the liquid by operation of the expansion jet near the triple point or above it,

or alternately above and below it and also P for the production of relatively large carbon dioxide crystalsby first maintaining pressure and temperature above the triple point to de osit hquid in the apparatus and thereafter to evaporate part of and to crystallize the rere ucing the pressure For all of these uses, an object of the invention is to provide a container of substantial capacity, that is liquid-tight and gastight, up to a desired level, above which level provision is made for escape of the gas, pref-v erably throu h a screen adapted to retain snow, when t e expansion jet is operated as a snow making jet.

One object of my invention is to insulating values of the cold gas produced by evaporation in the solidfyin process by usmg: as an insulating and re rigerating jacket tween the inner shell or .container for the solid carbon dioxide and the wall of an outer enclosing casing, which will be designed and constructed of strength sufiicient for the desired internal pressures and which for opalso for operation below the triple point, may be 300 pounds per s uare inch, to aifordsa desired margin of sa ety.

In snow making apparatus of a convention- ,removal of t e snow from the-snow chamber has been efiected either by causin the snow to pass directl involves peculiar comp ieations and difliculties, or by the more primitive method which however, that various fea-' utilize the the top of air is pra'cticallyall into a press, whlc ping the recess consists in temporarily sto mm the c amber and digging out the snow through a removable closure provided at the bottom thereof.

In all such apparatus the solid carbon dioxide adheres firmly to the inner wall of the container in which it is deposited, and has to be scraped or meltedtherefrom under conditions involving considerable waste. Moreover, when the manhole o1: closure at the lower end of the chamber is 0 en, a heavier than air carbondioxide gas bows out and warmerairballoons into the chamber, sublimating and wasting the snow or crystals at the center. of the mass but, for the most to the sides of the wall, the latter being ultimately freed mainly 1 heat conducted inward and warming up t e walls of the apparatus. If the moist a1r does come in contact with the inner surface of the shell, it deposits waterin the form of frost, thereby contaminating the product and renderin it still more diflicult to clean said walls. oreover, the entire shell is warmed up and must be recooled at great expense of liqu1d before the solidifyingr process can be restarted.

o obviate these difiiculties, I arrange the manhole in the top of the. chamber so that the'heavy gas, instead of flowing out is held by gravity within the chamber, and employ an inner can or. shell as the solidifying chamber which can be bodily withdrawn through the casing when the manhole cover is removed. The can itself is of approx mately the same diameter as'the o mug 1n the topof the casing and as it is' 'fted out through the. opening, the warm air warming the relatively thin wall of thecan uickly sublimates the negligible amount 0 solid CO re uired to free it from the can, with but little edect on the frozen mass.

The removal of the solid in its container and replacing it or substituting a, new one may be accomplished so quickly that the easing and gas therein heats up very little and kept out or driven out by the heavy cold. gas which hasv no opportunity to spill out of the casing.

The removable cans or shells in which the art not reaching the solid which is clinging snow is formed are preferably provided near their upper ends with vent openings permitting the CO gas generated in the solidifying process to escape into the space between the shell and the casing. Where snow is to be made, these gas Vents are rendered substantially impervious to the passage of snow by the provision of a screen, preferably carried by the casing and fitting snugly against the vented upper portion of the can in such a way as not to interfere with removal of the latter.

The above and other features of my invention may be more fully understood from the following description in connection with the accompanying drawing, in which Fig. 1 is a view mainly in vertical section through a snow making apparatus embodyin the invention;

ig. 2 is a transverse sectional view therethrough on the line 22 of Fig. 1; and

Fig. 3 is an enlarged vertical sectional detail showing the screen and the manner of supporting it.

The solidifying apparatus and connections has been shown more or less diagrammatically indicated, and it will be understoodthat the chamber or casing including cylindrical body 10, convex upper and lower heads 11 and 12 and manhole cover 13 may be externally lagged with insulating material.

The manhole in the upper head 11 has an annular frame member which includes an upstanding flange portion 16 snugly fitting within the opening 17 in the tank top and the laterally and downwardly flaring flange portion 18 lying under the head 11 and welded or otherwise secured thereto. This frame ring also provides an inwardly\ presented annular ledge member 19 upon which a band 20 surrounding the mouth of the can 14 is adapted to seat.

The inlet for the liquid carbon dioxide, shown as a snow making nozzle 15, is preferably carried by theplate 13 and is detachably connected in any convenient or conventional manner to a supply line for the liquid 00 this connection being uncoupled at times when the closure 13 must be removed to permit bodily removal of the can 14 and its solidified content.

The means for tightly sealing the cover 13 in lace includes clamping elements 21 remova ly mounted on bolts 22 fixed within bosses 23 on the head 11. Clamping gnombers 21 are formed firmly home against the edges of the cover 13 by tightening nuts 24 on. the upper exposed threaded ends of the bolts 22. Cover 13 is preferably flanged at 13a so that it snugly embraces the flange 16 as well as seating on it, it being understood that any suitable packing or gasket material ma be used at this point.

he container 14 which I have arbitrarily called a can,

is a relatively capacious cylin- 'drical formation open at its top and near its upper end being provided with a series of relatively large gas escape openings 25. When used for snow making, these openings are firmly backed by a cylindrical screen 26. This may include a central layer 26d of fabric and inner and outer layers 26b and 260 of Wire mesh.

The screen 26 is adapted to encircle and snugly fit the can 14. While it may be made bodily removable with the can,l prefer to make it as a separate unit which is permanently supported within the casing tank 10 and so positioned that when the can is slipped home the screen backs all of the gas outlet openings 25 in the upper end of the tank. To retain this screen in proper shape and to reinforce it,the upper and lower edges of the screen may be turned outwardly and secured by substantial ring members 27, respectively secured to the frame ring 18, 18

and to a sectional annulus 28 of angle iron,

the "expansion nozzle 15, partially crystallizes into snow and partially gasifies, the snow collecting in the can l land the intensely cold gas escaping through the openings 25 and through the screen 26 and flowing in the space between the tank and the can 14 where it provides an effective gas film insulation which aids to prevent sub imation of the snow which hasdeposited in the can.

If the back pressure is above the triple point, say 80 to 150 pounds, the liquid ;will flow to the bottom of the can, without formation of snow but a small part of it will evaporate sufficiently to maintain liquefying tern perature for the rest of it. Then the supply of liquid .will be cut olf and the valve :1: adjusted so as to permit any desired rate of boiling, thereby freezing to crystal form the remainder of the liquid. This operation may be repeated, if desired, to deposit the required amount of crystals.

clamps 21 removed or swung out of the way,

cover 13 carrying the nozzle lifting off, and the can 14 with its solidified content removed and the same or another can inserted.

As the can is lifted clear of the opening, there may be some slight tendency for the air to flow downwardly into the casing, but this remnant particles of the solid, will generate warm air stays on top and by sublimating the description, but it may be of various materials, and even fabric, and of any size and cross sectional shape to suit the requirements of the trade or the special circumstances of various snow making plants.

- I claim: p v

1. An apparatus for solidifying carbon I dioxide, including a chamber constructed to its top,

withstand internal pressures greater than pounds per square inch, having an o ening whereby it is accessible only through the top, a closure for said opening and meansadapted to discharge liquid carbon dioxide into the chamber and conduit for escape of gas, said conduit being formed or provided with means for imposing desired back pressure in said chamber.

2. A carbon'dioxide snow making machine, including a chamber having an opening therein, a closure hermetically sealing said open ing, a snow container monntedwithin the chamber and removable through the opening, said closure sealing both the chamber an snow container from the exterior. a nozzle adapted to jet liquid carbon dioxide into the container to produce oarbon'dioxide snow and gas, and means for discharging the gas from the container through the interspace between the chamber and the container. t

3. A carbon dioxide snow making machine, including a chamber having an opening therein, a closure for said opening, a snow con tainer mounted within thechamber and removable through the opening, a nozzle adapted to jet liquid carbon dioxide into the container to produce carbon dioxide snow and gas, and means permitting the escape of the gas from the container, and preventing the escape of snow therefrom, said means comprising a screen enc rcling the container and snugly fitting an a ertured portion thereof. 4. A carbon dioxlde solidifying apparatus, including a chamber having an opening in a closure hermetically sealing said opening, a receptacle for the solid insertable through the opening and depending into; the A chamber, said closure sealing both the ,chamher and snow container from the exterior, an expansion nozzlefor discharging liquid cars bon dioxide downward for expansion in the receptacle, said receptacle having .high level openings for escape of gaslaterally through said chamber.

5. A carbon dioxide expansion apparatus,

.for discharging a stream relatively slow rate. p I

makingsolid carbon .di

including a chamber having an opening in its.

top, a closure for said opening, a receptacle insertable through the opening, and depending into the chamber, an expansion nozzle of liquid carbon dioxide into the receptacle, the lower portion of said receptacle being gas tight and the upper portion having openings through which gas generated by the expansion is adapted to escape, and means to revent the escape of solid particles from sai openings, comprising a screen'encircling the receptacle and backing said openings.

- 6. A carbon dioxide expansion apparatus, including a chamber having an opening in its top, a closure for said opening, a receptacle insertable through the opening, and depending into the chamber, for discharging a stream of liquid carbon dioxide into the receptacle, the lower portion of said receptacle being gas tight and the upper por'tlon having openings through WhlCh gas generated by the expansion is adapted to escape, and means to prevent the escape of solid particles from said openings, com rising a screen encircling the receptacle and acking said openings, said screen comprising alternate layers of fabric and fine wire-mesh.

7. Apparatus as described in claim 5 and wherein both screen and container are of cylindrical formation "and the screen is supported on s. A method of making solid carbon dian expansion nozzle hanger means secured to the top of d the chamber,

oxide which includes enclosing a vented container in a gas-tight container, expanding liquid carbon dioxide into said vented container against an internal back pressure greater than 7 5 pounds per square inch, then venting gas to reduce said back pressure to boil said liquid at the triple point, thereby crystallizing' part of it, .then removing said vented container and contents.

9. A method of making solid carbon dioxide which includes charging liquid carbon dioxide into a container against an internal back pressure greater than 75 pounds per square inch, then ventin as to reduce said back pressure to boil sai llquid at the triplepoint, thereby cryst'allizing part of it.

10. A method of making solid carbon dioxide which includes charging liquid carbon dioxide intoa'container against an internal back pressure greater than: 75 pounds per square inch, then venting as to reduce said back pressure to boil said liquid at the triple point, thereby crystallizing part of it at a 11; .A method of oxide which includes charging liquid carbon dioxide into a water tight container against an internal back pressure greater than 75 pounds per square inch, then venting as to reduce said back pressure to boil said iquid lot eff; the triple point, thereby crystallizing part o it 12: A method of making solid Carbon d11- oxide which includes charging liquid carbon "dioxide into a Water tight container against an internal back pressure greater than 75 pounds per square inch, then venting gas to reduce saidback pressure to boil said liquid at the triple point, thereby crystellizing part of itat a relatively slow rate.

Signed at New York in the county of New York, and State of New York this 12th day of March, A. D. 1929.

' @I-iAS. L. JONES. 

